A comparison of LAI tests in human cancer by the Thomson tube method, said to measure cytophilic Ab, and Holt's microtest modification of the Halliday method, said to measure direct T-cell mediated immunity, is proposed. The laboratory assessment will evaluate PBS versus 3M KCl tumor extracts in each method and identification of the affected non-adherent cells by cytochemical staining, sheep erythrocyte and SIg receptors, latex ingestion, and several anti-human T-cell antisera. Previous work by the proponents has demonstrated lability of PBS tumor extracts frozen at -20 degrees centigrade. A comparison of functional stability of the PBS and KCl extracts using liquid nitrogen storage and lyophilization is to be made. The clinical protocol will be a blinded evaluation of patients with cancer and benign disease as well as healthy, normal individuals with extracts of human tumors found to be positive in the laboratory evaluation phase. The results of the LAI test and blocking factor will be analyzed versus several other tests of nonspecific immune function, stage of disease, tumor burden, and other laboratory tests appropriate to the types of cancer under study (e.g., CEA in GI malignancy).